On the Newtonian limit in gravity models with inverse powers of R

I reconsider the problem of the Newtonian limit in nonlinear gravity models in the light of recently proposed models L-grav similar to root - g f (R) with inverse powers of R. Expansion around a maximally symmetric local background with curvature scalar R-0 > 0 gives the correct Newtonian limit on length scales much less than R-0(-1/2) if the gravitational Lagrangian root - g f (R) satisfies \ f (R-0) f"(R-0) \ much less than 1, and I propose two models with f"(R-0) = 0.